Methods of manufacturing such portable objects, especially cards, are known, for example in document U.S. Pat. No. 6,088,230, in which the antenna, consisting of a conducting wire, is first connected by one end to a contact on a chip placed on a substrate, then placed on the substrate with a wire guide and insertion means which are moved bi-axially across the surface of the substrate (along X and Y axes). When the antenna follows a meandering path, connection points are necessary at each change of direction.
To make these connection points, the insertion means must be lowered along a Z-axis and the conducting wire is temporarily pressed against the surface of the substrate and then pressed and thermally welded in the substrate. Lastly, the second end is connected to another contact of the chip, and the substrate and its components can then be covered by a protective layer.
The steps involved in producing a card with chip and antenna are difficult, especially when the antenna is not straight.
In addition, the antenna is not held in place before being covered with the protective layer, making it impossible to guarantee its position.
The European patent application published under number EP 0 841 634 concerns a method of manufacturing an integrated circuit card comprising an antenna comprising at least one turn in which a unique housing is made to contain said antenna.
The U.S. Patent published under U.S. Pat. No. 6,021,949 concerns a gaming token comprising an electronic identification element and an antenna. The antenna may comprise a plurality of turns which are placed in a unique housing.
By placing an antenna comprising a plurality of turns in a unique housing there is some disadvantages. During, for example, an injection step following a positioning step in which the antenna is placed in the unique housing, the position of the turns can namely vary, thus modifying the geometry of the antenna. By modifying the geometry of the antenna, there is a risk that the operating frequency of the portable object can be less precisely defined. So the portable object obtained by such a method can be less reliable.